With the continuous advancement and improvement of electronic technology and communication techniques, compact or portable electronic devices such as cellular phones, personal digital assistants (PDAs), PDA phones, car PCs, etc, are also evolving rapidly. The electronic devices in the market now have integrated a greater number of functions to increase their competitiveness. Other than the conventional functions of taking photos, making phone calls, and surfing the internet, the global positioning system (GPS), the electronic map, the navigation system are also integrated in a handheld communication device. Hence, a user can monitor his/her location through the electronic map and the GPS anytime. Also, by the planning and guiding of the navigation system, the route can be determined to reach the destination.
However, the GPS can only function in places with satellite signal reception. Once the user carries the GPS into a building or other places with satellite signal blockage, the positioning will not be proceeded correctly. Under such conditions, when the user needs to position his/her location, he/she can only position his/her location at a place with satellite signal reception, such as a window side, outdoors, etc. Thus, an alternative way must be provided as an option for the user to position his/her own location anytime and anywhere.